Many modern commercial aircraft are designed to withstand impacts with small objects (e.g., birds) without affecting the safe operation of the aircraft. While impacts with certain small objects may not generally affect the safety of the aircraft, such impacts may have effect on the aerodynamic performance of the aircraft or create other inconsistencies of operation.
Furthermore, aircraft regulatory rules may require a diversion or turn back of the aircraft or enhanced inspections of the aircraft if an object strikes the aircraft even if the strike does not result in any damage. As a result, mid-air impacts may result in significant costs for an airline and other aircraft operators.
However, impacts with small objects may be a safety issue for certain non-commercial aircraft. For example, unmanned aerial vehicles and other relatively small aircraft may have less capacity to carry systems and structures that are resistant to damage from a bird strike. A bird strike may cause a significant issue for aircraft with stealth capabilities by causing inconsistencies in the coatings or other features than make the aircraft stealthy.
Additionally, even a relatively small object can cause significant surface damage to the aircraft. For example, a small bird colliding with an airplane (e.g., at takeoff or cruising speeds) may impact with a force of about two tons or more.
The majority of historical bird strikes occurred at altitudes below 3000 feet. Typical current bird detection and avoidance systems and schemes are ground based (e.g., dogs, falcons, air cannons, and radar systems) and are ineffective at distances beyond an airport and do not protect from mid-air strikes throughout the movement envelope.